I'm using a software called MAGIX, it's not expensive and it gives you a lot of possibilities. I'm still a beginner. If you visit Ernst Stolz(ernststolz) on YouTube you can see what is possible with this software. He is very good, I have made some virtual duets with him and he has mixed the videos.
For the sound I use a Korg D4 digital recorder. When I'm satisfied with the video, I add the audio. It's very simple.